Different communication service providers typically utilize different and often incompatible communication networks. As a result, mobile phones used in one communication network may use different vocoders to convert speech to digital signals and digital signals to speech than mobile phones used in another communication network In order for mobile phones with different vocoders to communicate with each other, a transcoder is required to convert between the vocoders. Transcoders are typically deployed in communication gateways. The communication gateway receives the call initiation information from a call initiator trying to contact a call target. The communication gateway then contacts the network associated with the call target, determines the vocoders supported by the network and sets up a transcoder to translate between different vocoders.
A group dispatch call is a call that allows a user to contract a group of individuals and speak to them all at once. When a group call takes place within the same network, each participant is using compatible equipment and no transcoder is required. However, group calls that include participants in different networks typically require the use of transcoders. Since a large number of individuals can be part of a group call, the potential number of transcoders that have to be setup can be very large. For example, in one embodiment there can be up to twenty-one (21) participants to the group call. If each participant is in a network that uses a different vocoder than the call initiator, up to twenty (20) possible transcoders are needed to support the delivery of voice from the original call initiator to the other participants in the group call. When the speaking party switches from the call initiator to another party to the call, a different set of twenty (20) transcoders may need to be used. Therefore, at worst case a total of two-hundred and ten (210) different transcoders will be needed to support the group calls. Because of this large requirement of transcoding resources, what is needed is a method for optimizing transcoders for group dispatch calls.